For controlling the operation of a household appliance using a conventional rotary selector switch, a control panel must have a hole therethrough for a shaft to transmit the rotary position of the rotary selector switch to the evaluation electronics disposed behind the control panel. Until now, the evaluation of the rotary position has been performed on the operating and display electronics behind the fascia panel. Depending on the appliance, incremental or absolute evaluation methods may be used. Commonly used technologies include, inter alia, optical evaluation using encoding disks, encoders, bit generators, potentiometers and mechanical switching contacts. All of these technologies require a through-hole in the fascia panel to mechanically transmit the rotational angle.
EP 0 844 325 A2 describes an operating and display device.